“The Cutie Re-Mark” showed altering time didn’t stop them from getting the same cutie marks, just the circumstances that led to them connecting.

Cutie marks are stated to represent ponies talents, so they are connected to destiny failing it won’t change the mark, as what made it was already established.

Did you really draw this, OP?

Because I don’t think you did.

@Background Pony #2D18
I do think it’s “Friendship.” When the Rainboom happened, it was like… a prophesized event, if you don’t mind me being mysterious. In that moment, all six of them got their marks almost in unison; it likely even tipped Celestia off that they were the Element Bearers. I can’t help but imagine that is a common occurrence. And with their Marks lining up with the Tree of Harmony’s gemstones, Celestia probably knew what they were destined to be.

@Background Pony #B0A0
To be fair, Luna’s Cutie Mark did change when she became Nightmare Moon, though not by much. The “sky” of the mark became a dark purple - likely a design choice to keep it from vanishing into her now-black coat, but the moon also was shifted from white, to a light-blue. That change wasn’t needed, from a design perspective, and I can only imagine symbolized her transformation in identity. The same could be seen with Nightmare Rarity in the comics; her three diamonds became three light-blue “stars,” surrounded by several smaller white stars.

Honestly, Cutie Marks were one of the most nebulous and least explained concepts in the series. They explained how they impacted the lives of the ponies, but many of their traits are still a mystery.

By that logic all of the mane 6s talents would disappear as they all are on the tree of harmony. Or Luna’s should have after she became NMM. Yet another poor excuse by twi gang.

When does anyone’s cutie mark disappear because they didn’t meet a goal? When has a cutie mark’s interpretation been so black and white?

The point is that they’re fated special talents, and that you can make the most of whatever your talent is.

If her special talent is not magic or friendship, why did it appear when she was hatching Spike? The Sonic Rainboom that tied them all together was the only other thing happening at the same time, which didn’t really involve the Elements lol. Just friendship.

Well, if you think about it, her mark isn’t for the Elements, but for each of her friends. The fact that her mark was predicted by the Tree of Harmony implies some degree of pre-cognition, or future sight.

Ever since finding the Elements, Celestia had been on the lookout for ponies who’s marks matched the crystals. She saw they were all gathered in Ponyville, except for one, which she sent there, knowing it would end in them all united. Her Cutie Mark was one of pre-destined friendship; fitting for the Princess of Friendship. And what is Friendship? Magic.

Friendship is a magical boosting force, at least for Twilight and the Elements. With her friends there, she is infinitely more powerful than when she was alone.

But that’s just my theory.